In the construction site of building foundations, differences in the types of foundation soil can have varying impacts on drilling operations. Reverse circulation drills need to be adjusted accordingly to address these situations. When dealing with highly viscous soil, the mud circulation system of the reverse circulation drill comes into play. By delivering mud with moderate viscosity, it encapsulates the soil particles around the drill hole, reducing the adhesion of soil to the inner wall of the drill rod and preventing blockage of the drill hole due to soil agglomeration. Simultaneously, workers will appropriately control the drilling speed to allow sufficient time for the mud to carry away the fragmented soil blocks, maintaining the smoothness of the drill hole.
When encountering sandy soil, anti-collapse measures for reverse circulation drills are particularly crucial. Such soil particles are loose, and the borehole wall is prone to collapse. At this time, the mud from the drill will increase in density, forming a protective film on the borehole wall to enhance its stability. In addition, the drill bit of a reverse circulation drill is designed with a spiral structure. During drilling, it can both break up sandy soil and quickly transport it to the surface through the spiral blades, reducing the possibility of sandy soil accumulating in the borehole and further lowering the risk of hole collapse.
If there is soil with interlayered stones in the construction area, the focus will be on the material and speed adjustment of the drill bit of the reverse circulation drill. The drill bit will be made of wear-resistant alloy material to cope with the impact and wear from the stones. At the same time, the staff will reduce the drilling speed and increase the torque to allow the drill bit to gradually break up the stones, avoiding damage to the drill bit or stones getting stuck in the borehole due to excessive speed. The broken stones will be brought out of the ground along with the mud circulation system, ensuring that the borehole can be advanced to the designed depth.